Speed changer

Abstract

A speed changer includes an inner ring, an outer ring, a plurality of first tapered rollers provided in an annular space between inner ring and outer ring on one side in an axial direction, annular first cage that holds the first tapered rollers, a plurality of second tapered rollers provided in the annular space on the other side in the axial direction, and an annular second cage that holds the second tapered rollers. The first cage is a fixed member that is not allowed to rotate around a center line of the annular space. The outer ring is an input member to which a rotation torque is input. The second cage is an output member that outputs rotation resulting from reduction in a speed of the input. A first rotating portion including the first tapered rollers is different in specifications from a second rotating portion including the second tapered rollers.

What is claimed is: 
     
       1. A speed changer comprising:
 an inner ring; 
 an outer ring; 
 a plurality of first rolling elements provided in an annular space between the inner ring and the outer ring on one side in an axial direction; 
 an annular first cage that holds the first rolling elements; 
 a plurality of second rolling elements provided in the annular space on the other side in the axial direction; and 
 an annular second cage that holds the second rolling elements, wherein 
 the first cage is a fixed member that is not allowed to rotate around a center line of the annular space, 
 the inner ring or the outer ring is an input member to which a rotation torque is input, 
 the second cage is an output member that outputs rotation resulting from a reduction in a speed of the input, and 
 a first rotating portion including the first rolling elements and raceways of the inner ring and the outer ring on which the first rolling elements roll is different in specifications from a second rotating portion including the second rolling elements and raceways of the inner ring and the outer ring on which the second rolling elements roll. 
 
     
     
       2. A speed changer comprising:
 an inner ring; 
 an outer ring; 
 a plurality of first rolling elements provided in an annular space between the inner ring and the outer ring on one side in an axial direction; 
 an annular first cage that holds the first rolling elements; 
 a plurality of second rolling elements provided in the annular space on the other side in the axial direction; and 
 an annular second cage that holds the second rolling elements, wherein 
 the first cage is a fixed member that is not allowed to rotate around a center line of the annular space, and the second cage is an input member to which a rotation torque is input, 
 the inner ring or the outer ring is an output member that outputs rotation resulting from an increase in a speed of the input, and 
 a first rotating portion including the first rolling elements and raceways of the inner ring and the outer ring on which the first rolling elements roll is different in specifications from a second rotating portion including the second rolling elements and raceways of the inner ring and the outer ring on which the second rolling elements roll. 
 
     
     
       3. The speed changer according to  claim 1 , wherein the first rolling elements and the second rolling elements are tapered rollers,
 the inner ring or the outer ring is axially divided into a first division ring and a second division ring each having the raceway, and 
 the first division ring and the second division ring are clamped together with an axial preload imposed on the first division ring and the second division ring using a clamping member. 
 
     
     
       4. The speed changer according to  claim 2 , wherein the first rolling elements and the second rolling elements are tapered rollers,
 the inner ring or the outer ring is axially divided into a first division ring and a second division ring each having the raceway, and 
 the first division ring and the second division ring are clamped together with an axial preload imposed on the first division ring and the second division ring using a clamping member. 
 
     
     
       5. The speed changer according to  claim 3 , wherein the clamping member has a shaft member or a tube member which is provided across the first division ring and the second division ring. 
     
     
       6. The speed changer according to  claim 4 , wherein the clamping member has a shaft member or a tube member which is provided across the first division ring and the second division ring. 
     
     
       7. The speed changer according to  claim 1 , wherein the first rolling elements and the second rolling elements are tapered rollers,
 a through-hole centered around a roller center line is formed in each of the tapered rollers, 
 each of the first cage and the second cage has a pair of annular portions provided on opposite sides of the tapered rollers and shaft portions coupling the annular portions together and each passing through the corresponding through-hole, and 
 needle rollers are interposed between each of the through-holes and the corresponding shaft portion. 
 
     
     
       8. The speed changer according to  claim 2 , wherein the first rolling elements and the second rolling elements are tapered rollers,
 a through-hole centered around a roller center line is formed in each of the tapered rollers, 
 each of the first cage and the second cage has a pair of annular portions provided on opposite sides of the tapered rollers and shaft portions coupling the annular portions together and each passing through the corresponding through-hole, and 
 needle rollers are interposed between each of the through-holes and the corresponding shaft portion. 
 
     
     
       9. The speed changer according to  claim 3 , wherein the first rolling elements and the second rolling elements are tapered rollers,
 a through-hole centered around a roller center line is formed in each of the tapered rollers, 
 each of the first cage and the second cage has a pair of annular portions provided on opposite sides of the tapered rollers and shaft portions coupling the annular portions together and each passing through the corresponding through-hole, and 
 needle rollers are interposed between each of the through-holes and the corresponding shaft portion. 
 
     
     
       10. The speed changer according to  claim 4 , wherein the first rolling elements and the second rolling elements are tapered rollers,
 a through-hole centered around a roller center line is formed in each of the tapered rollers, 
 each of the first cage and the second cage has a pair of annular portions provided on opposite sides of the tapered rollers and shaft portions coupling the annular portions together and each passing through the corresponding through-hole, and 
 needle rollers are interposed between each of the through-holes and the corresponding shaft portion. 
 
     
     
       11. The speed changer according to  claim 5 , wherein the first rolling elements and the second rolling elements are tapered rollers,
 a through-hole centered around a roller center line is formed in each of the tapered rollers, 
 each of the first cage and the second cage has a pair of annular portions provided on opposite sides of the tapered rollers and shaft portions coupling the annular portions together and each passing through the corresponding through-hole, and 
 needle rollers are interposed between each of the through-holes and the corresponding shaft portion. 
 
     
     
       12. The speed changer according to  claim 6 , wherein the first rolling elements and the second rolling elements are tapered rollers,
 a through-hole centered around a roller center line is formed in each of the tapered rollers, 
 each of the first cage and the second cage has a pair of annular portions provided on opposite sides of the tapered rollers and shaft portions coupling the annular portions together and each passing through the corresponding through-hole, and 
 needle rollers are interposed between each of the through-holes and the corresponding shaft portion.